Fox News is reporting that five people described as anarchists were arrested Monday in a Cleveland-area park for allegedly trying to blow up a bridge.

The public was never in danger from the explosive devices, which were inoperable and controlled by an undercover FBI employee, according to sources close to the investigation.

A criminal complaint was filed Tuesday morning in U.S. District Court in Cleveland. Court documents say three of the suspects are self-proclaimed anarchists who formed a small group and considered a series of plots over several months.